1. Field
The present embodiments relate to power-protection techniques. More specifically, the present embodiments relate to power-protection circuits for use in a multi-level power hierarchy.
2. Related Art
A wide variety of power-protection techniques, such as fuses and circuit breakers, are used to prevent circuits from being damaged in the event of an overload condition. As circuits and devices are combined into larger-scale systems, these power-protection techniques are used at different levels in these systems to provide overload protection as power from lower levels is aggregated at higher levels.
It is often difficult to provide appropriate power protection in many systems. For example, FIG. 1 presents a block diagram illustrating an embodiment of an existing data center 100, which includes a bus 110 that has a series of arms A-C. Each of these arms includes multiple devices, such as servers 116. Power protection at a high level in the data center 100 may be provided by circuit breaker 112, and at lower levels, such as in the arms A-C, by circuit breakers 114.
Within data center 100, a given server, such as server 116-1, may have a power consumption corresponding to a maximum current of 2 A, but may only use 1 A under normal operation and 0 A at idle. However, circuit breakers 112 and 114 are often set to high values corresponding to the worst-case possible power consumption. Consequently, circuit breakers 112 and 114 may be over provisioned, which significantly increases the expense of these components.
On the other hand, if lower settings are used for circuit breakers 112 and 114, the uninterrupted operation of significant portions of the data center 100 may be jeopardized. In particular, because the loads executing on the servers 116 vary over time, multiple servers 116 are often included on a given arm (such as arm B) of bus 110 to make best use of the infra-structure in data system 100. However, if one of the circuit breakers 114, such as circuit breaker 114-1, is tripped by an overload condition, multiple servers may loose power.
Additionally, it is also difficult to address this problem using software. For example, in principle software can be used to keep the data center 100 from concurrently running a set of applications that results in power spikes associated with external demands (such as requests from remote users). However, in practice software typically cannot respond fast enough to prevent such power spikes from occurring.